The top three aphids (small green and two large blackish green) are green morphs, and the lower two aphids (small red with an ant and a large brownish green) are red morphs.Credit : Photo by Ryota Kawauchiya. (Watanabe S. et al., Scientific Reports, February 2, 2018)

Ants and aphids coexist in a symbiotic relationship that benefits both species. Ants protect aphids from predators, such as lady bugs and wasps, and aphids secrete nutritious honeydew for ants to eat.

The aphid species Macrosiphoniella yomogicola comes in two “morphs” with distinct colors: red and green. When there is more than one physical trait of the same species, it is called polymorphism. Typically, competition for survival would lead to one morph dominating and the others disappearing from the gene pool. However, this rule can be broken in a few circumstances, including if an ant benefits from maintaining a mixture of color morphs.

Previously, Associate Professor Eisuke Hasegawa of Hokkaido University and his colleagues had determined that Lasius japonicus ants prefer the nutrient-rich honeydew produced by green morphs. They also found that ants were most attracted to and most vigorously protected colonies with 65% green and 35% red aphids.

In a new study published in the journal Scientific Reports, Hasegawa and his students, including Saori Watanabe, investigated how population growth of aphid morphs differs with or without the presence of ants. They found that ants actively manipulate morph populations by improving the reproduction rate of the inferior morph.

In field experiments without the ants’ presence, the red morphs had a much higher and superior reproduction rate than green morphs. Thus, red aphids should dominate. However, when ants were introduced to the experiment, the green morph reproduction rate equalized with the red morphs.

The experimental evidence matches what researchers find in the wild: red and green morphs coexisting on the same plant shoots attended by ants.

What remains a mystery is this: if the ants prefer the green morphs’ honeydew, why keep the red morphs around at all? Hasegawa explains, “We theorize that the red morphs are able to provide a benefit that the green morphs can’t, such as suppressing the development of lower buds on host plants. This might help both the red and green aphids survive and reproduce throughout more of the year, which could maximize long-term harvest of honey-dew from the green aphids.”

“In this case, the ants invest in a future benefit by sacrificing the present benefit,” the researchers hypothesize. They plan to test this hypothesis next.

Aims of RevoScience

Research in basic science and technology in our country is far behind in comparison to our neighboring countries. This is the time to think what we can do. The magazine will act as a platform for us where we can come together to make proposals, plans and interact with each other. Such interaction will expand our horizon to develop nation and ourselves.

At first glance, this image may resemble red ink filtering through water or a crackling stream of electricity, but it is actually a unique view of our cosmic home. It... The post Our galaxy’s heart appeared first on RevoScience.

Low rises on the ocean floor at a depth of 5,500 meters in the western North Pacific regulate surface flows and create sharp sea surface temperature (SST) fronts, which have... The post The far-reaching effects of ocean floors on the sea surface appeared first on RevoScience.

State-level policy in the U.S. is responsive to public opinion, study shows. CAMBRIDGE, MA — In politics, your voices make a difference. At least at the state level of U.S.... The post People power appeared first on RevoScience.

Supersonic gas streams left over from the Big Bang likely gave rise to early massive black holes. The mechanisms that drive black hole formation and growth are poorly understood. An... The post Unravelling the mystery of black hole formation appeared first on RevoScience.